The reserve covers Lake Mętne and the neighbouring marshes. This area is dominated by plant communities typical of poor fens and high peat bogs. Shrub birch, for the protection of which the reserve was established, is included in the Polish Red Data Book of Plants, and remains under strict protection. The reserve is also home to the pygmy damselfly, a protected species considered highly endangered in Poland.

The reserve also features many other interesting species of plants and animals, such as round-leaved sundew, wild rosemary, mud sedge, common European adder, grass snake and slow worm. Lake Mętne Reserve is also a crane refuge. While it is closed to tourist traffic, you can get close to the reserve by heading north from Rytel, towards the Ostrowy forester’s lodge.